Epson 3800 - Stylus Pro Color Inkjet Printer Service Manual page 42

EPSON Stylus Pro 3800/3800C/3850
2.3.2.1 Pressure Pump Unit Mechanism
† Accordion unit/Pressure pump motor/Pressure pump home sensor
The accordion unit intakes air and applies pressure by the rotating drive of the pressure
pump motor, and pumps air into the ink cartridges. The pressure pump home sensor
detects the position of the accordion unit.
Pressure pump motor
Combination Gear, 18, 39
CW rotation
Applying
pressure
Spur Gear, 24.5
Accordion Unit
Figure 2-7. Drive Transmission Path
† Pressure sensor unit
A reflective photo sensor, which turns on when the air pressure reaches the
predetermined level, controls the amount of pressure. When the air pressure reaches
the predetermined level, film on the air damper expands and activates the reflective
plate causing the sensor to receive light, and the pressurizing state is detected.
† Regulator
Stops applying pressure when the power is off or during stand-by. Activated by the
pressure pump motor through the clutch. The regulator opens the valve to reduce
pressure.
OPERATING PRINCIPLES
CCW rotation
Reducing
pressure
Spur Gear, 22
Clutch
Regulator
Ink Supply Mechanism
Applying pressure
Valve
CW rotation of the
clutch closes the valve
and applies pressure to
send air toward the ink
cartridges.
Reducing pressure
CCW rotation of the clutch opens
the valve and reduces pressure.
When the air pressure reaches
the predetermined level, the
valve opens as the pressure
overcomes the tension of the
spring that presses the valve.
Pressure Pump
Home Sensor
Spur Gear, 24.5
Accordion Unit
Sensor
Air Damper Film
Figure 2-8. Pressure Pump Unit
Revision A
Clutch
Combination Gear 18, 3.9
Clutch
Regulator
Spur Gear, 22
Pressure
Pump Motor
Pressure Sensor Unit
42